Aesti

The Aesti (also Aestii or Aests) were an ancient people first described by the Roman historian Tacitus in his treatise Germania (circa 98 CE). According to Tacitus, Aestui, the land of the Aesti, was located somewhere east of the Suiones (Swedes) and west of the Sitones (possibly the Kvens), on the Suebian (Baltic) Sea. This and other evidence suggests that Aestui was in or near the present-day Russian enclave of Kaliningrad Oblast (previously East Prussia).

Geographical and linguistic evidence suggests that the Aesti were, ethnologically, a Baltic people. They may have been synonymous with the Brus/Prūsa or "Old Prussians" – that is, not a Germanic people like modern Prussians, and not a Finno-Ugric people, such as modern Estonians. Tacitus almost certainly erred in implying that the Aesti were a hybrid Celtic-Germanic culture: he claimed that while the "Aestian nations" followed the "same customs and attire" as "the Suebians" (at the time a collective term for eastern Germanic peoples), their speech resembled that of the Britons (i.e., a Celtic language rather than the Germanic languages of the Suebii). Tacitus often utilised unreliable, secondary sources, and may not have been aware of such distinctions in any case.